in-cone primitive | NetLogo Dictionary

in-cone

in-cone is a primitive that allows for simulating a "cone of vision" in front of a turtle. This allows us to simulate an agent having some sight or other sense in front of them, but not behind or to the side of them.

The cone is constructed with two inputs: how far the agent can see (the radius), and how wide the agent can see (the number of degrees, anywhere from 0 to 360). For instance, if we wanted some rabbits to eat if there were carrots in front of them, but not behind or to the side, we could say

ask rabbits [
  if any? carrots in-cone 3 45 [ eat ]
]

Note that like in-radius, in-cone can end up reporting itself. Be sure to account for that in your models if need be with the other primitive.

In this example model, in-cone is used to simulate 4 motion-activated wildlife cameras. When a camera detects that there are any? animals in-cone 8 50, it will turn yellow to simulate taking a picture. (Note that the highlighted patches are just to better visually show the cone of vision. In actuality none of the in-cone turtle detection has anything to do with which patch a turtle is standing on.)

Try it Yourself

Limited Editing

breed [cameras camera]
breed [animals animal]

to setup
  clear-all
  reset-ticks

ask patches [
    set pcolor green
  ]

create-cameras 4 [
    set shape "arrow"
    set color grey
    set size 2
  ]
  layout-circle cameras 2 ;; arrange the cameras in a circle around the center

ask cameras [ ;; highlight the area that the cameras can see
    ask patches in-cone 8 50 [
      set pcolor green + 1
    ]
  ]

create-animals 2 [
    set shape "wolf"
    set color brown
    set size 1.5
    setxy random-xcor random-ycor
  ]

crt 1 [ ;; create a tree for the cameras to wrap around (for the visual)
    set color green - 1
    set shape "tree"
    set size 2
  ]

end

to go
  ask animals [
    right random 90
    left random 90
    fd random-float 1
  ]

ask cameras [
    ifelse any? animals in-cone 8 50 [ ;; if I see any animals in my cone of vision
      set color yellow                 ;; light up
    ] [                                ;; otherwise
      set color grey                   ;; set my light to off
    ]
  ]
  tick
end

Limited Editing

Error

NetLogo Web has encountered a problem.

It looks like you're using NetLogo Web in standalone mode.
If the above error is being caused by an unimplemented primitive, we recommend a quick visit to NetLogoWeb.org to see if the primitive has been implemented in the most up-to-date version.

What's next?

Once you mastered the in-cone primitive, don't stop there. Check out the resources below to improve your NetLogo skills.

in-cone

Try it Yourself

Error

What's next?

Similar primitives:

`in-radius`

`other`

`neighbors`

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